Save our Sonics defense
What Seattle's revolutionary S-O-S scheme from the early-90s can teach us about the future of NBA defensive strategy.
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Cassian Andor: defensive guru.
Something interesting was happening in the NBA before COVID-19 shut the league down. It’s best summed up by this nugget from friend of the program Ben Falk, a former high-ranking NBA executive who now runs the most indispensable basketball stats site on the web.
Shooting accuracy is the most important factor to winning, especially once the league finally realized that three is greater than two. Since there hasn’t been much evidence that defenses have significant control over opponent three-point percentage over multi-year samples, the prevailing view is that good defenses succeed because they prevent threes from being taken in the first place.
Yet as Falk’s tweet notes, many of the best defenses in the league this season were also the ones that let their opponents fire away a ton from downtown. Modern conventional wisdom concludes they’re doing it all wrong. The standings tell a different tale.
In particular, check out the Milwaukee Bucks and Toronto Raptors. They’re the two best teams in the East for the second straight season. They’re No. 1 and No. 2 in opponent three-point attempts surrendered per game. They’re also the two best defenses in the league.
Their strategies could not be more different. Milwaukee has a hyper-conservative scheme that keeps their biggest players at the rim, while Toronto relies on manic perimeter pressure that spooks their opponents. One allows three-pointer attempts because they never rotate on defense; the other allows them because they’re rotating constantly. (If you want to read more about both teams’ approach, check out my SB Nation pieces on the Bucks’ rim emphasis and the Raptors’ relentless pressure).
While the Bucks’ approach builds on the tenants of Gregg Popovich’s Spurs and Tom Thibodeau’s Bulls, the Raptors’ style seems more novel. Nick Nurse is so creative! Who else would try a Box-and-1 in the Finals? Who else would try a full-court press? What other team can seamlessly switch between man-to-man and zone defense, sometimes on the same possession? Who else would think to brand their own hats?
In researching my SB Nation haunted house piece, I found a noteworthy historical parallel: the beloved 1990s Seattle Supersonics. They got a brief mention at the end of that article, but with no live basketball happening, I’ve found myself diving deeper into old Sonics games.
Two things became clearer:
The Sonics really were the spiritual ancestor of the current Raptors.
There’s a lot the modern game can learn from their philosophy, even though they played in a different era.
What was the Sonics’ system anyway?
Time to send an SOS to the world! Bob Kloppenburg’s S-O-S defensive system, that is. (I’m sorry).
A Sonics assistant coach from 1985-1995, Kloppenburg pioneered an aggressive system of traps, ball pressure, and double-teams designed to mess up the offense’s rhythm. It funneled ball-handlers to “checkpoints” on the court where they’d be especially vulnerable to swarming defenders. Here’s one of many examples:
The six main tenants of the system translate nicely to today’s NBA. To eliminate any hesitation, Kloppenburg emphasized switching most on- and off-ball screens. Hey, that sounds familiar! The Sonics also double-teamed at unpredictable times using different defenders, and often hounded point guards for 94 feet. It’s called the “S-O-S” system because every word the team used to call out coverages began with one of those letters. (For example: “screen,” “over,” and “switch” are the words used to communicate the plan on off-ball picks).
The S-O-S system was unique for its time because it required all five players working on a string to close space and cut out obvious passing options. It functioned like a zone defense, even though the NBA didn’t allow zone at the time. The Sonics led the league in illegal defense calls by a mile when they used S-O-S as their primary scheme, but they were undeterred. In half-court situations, they timed their double-teams so the other three defenders were close enough to the four remaining offensive players to be “guarding” them according to the NBA rulebook.
One Seattle specialty: trap the ball as soon as a guard began running off a down screen. That allowed Derrick McKey to cover two players at once while only “guarding” his own guy.
The Sonics knew referees couldn’t call illegal defense on every play. Were they really going to whistle this play dead because Eddie Johnson wasn’t in a legal guarding position for a split second miles away from the ball? Of course not.
Kloppenburg was a Sonics assistant for a decade, but he was most empowered after George Karl took over midway through the 1991-92 season. Kloppenburg’s system was perfect for Karl’s mad scientist vibe, so Karl embraced it as Seattle’s full-time scheme. (“This guy wants to double-team Jesus,” Karl once said of Kloppenburg.).
That decision immediately turned Seattle into a contender. The Sonics won nearly 70 percent of their games over the next three-and-a-half seasons while ranking in the top 10 in fewest points allowed per 100 possessions and near the top in turnovers created. In their banner 1993-94 season, they forced teams to give the ball away on 18.2 percent of their possessions, by far the best in the league. The difference between them and second was as large as the difference between second and 17th.
Stars, particularly point guards and post players, hated playing against them. Just ask Hakeem Olajuwon, who compiled a 6-20 record against the Sonics from 1992 to 1996 and suffered his only two playoff series defeats in that span. What good were Olajuwon’s deadly post moves if he never had time or space to execute them?
How else was Seattle ahead of its time?
You may have heard of the “scram” switch, an off-ball maneuver designed to mitigate mismatches inside. When a guard and big man switch a pick-and-roll, that leaves a small guy stuck momentarily on a big man in the mid- or low-post. To account for that, a third player – usually the next-biggest man on the team – will simultaneously leave his man on the opposite side and pick up the screener in the post. (Here’s a good explanation from the great Zach Lowe.) The Raptors use scram switches to stop post-up threats, but also deploy the same tactic to prevent drives into the teeth of the defense.
Scram switching is a natural reaction to the league becoming more positionless. If all five offensive players can handle, shoot, and pass, all five defenders need to be proficient at defending each position.
But scram switching isn’t entirely new. In executing the S-O-S scheme, the 90s Sonics became masters at it. Ignore Muggsy Bogues and watch all the activity on the baseline.
Watch how Shawn Kemp, Nate McMillan, Gary Payton, and Sam Perkins keeping passing off Charles Barkley and the Suns’ many cutters to alleviate any danger.
Payton was the defensive star of the team, but Kemp and Perkins were critical to the system’s success. Kemp was the omnipresent help defender, flying in from the opposite side to swat shots and snatch rebounds out of the air. You might not associate Kemp with modern do-everything defenders like Draymond Green and Pascal Siakam, but he played a similar role for the Sonics’ defense. Look how much Kemp moved on this play.
(Kemp was nearly traded to the Bulls for Scottie Pippen after the 1993-94 season, but the deal was nixed by Sonics ownership. Imagine Pippen playing that rover role in Kloppenburg’s S-O-S instead of Kemp. That would have been revolutionary).
But Kemp’s defensive range was only effective because of Perkins’ dirty work as a man-to-man defender. While Kemp delivered right hooks, Perkins supplied crucial body blows. He was the player switching on- or off-ball screens, jostling with top post players, funneling the ball into Seattle’s waiting traps, or sprinting over from the opposite side to double-team the point guard. He could contain the biggest threat at the NBA’s version of the line of scrimmage, whether it was out here.
Or anywhere in between.
Because Perkins could plant himself between the ball and the basket effectively against any kind of player, the other Sonics could swarm effectively to force turnovers or confusion. If necessary, Perkins could also anchor the back line when others got more involved at the point of attack. He didn’t have one obvious defensive strength, but he was pretty good at everything, which freed other Sonics to fly around everywhere.
(Here’s a hot take: I think Perkins is the most underrated player in NBA history. He did everything us nerds love about pre-Sixers Al Horford – including three-point shooting – and never got the credit because he came up in an era when big men were expected to be dominant scorers instead of ace role players).
The rest of the Sonics slotted in around Payton’s ball pressure, Perkins’ versatility, and Kemp’s looming shadow. The Sonics traded a lockdown wing in McKey for the offensive-minded Schrempf after the 1993 season and got better defensively. With so many like-sized players that could defend anywhere and an emphasis on a five-man unit tied together at all times, the Sonics would have fit in perfectly in today’s pace-and-space era.
So they switched a lot, forced turnovers, and had a versatile group of players. Whoop de doo.
Hey, that’s pretty revolutionary for the 90s!
That said, the real reason the Sonics offer lessons for modern teams is that they used their defense to trigger offense, not the other way around. To quote a 1993 story by Seattle Times reporter Glenn Nelson: (Emphasis mine).
That style is built in part on contradictions. Such as offense begins at the defensive end.
"We used to say that, if you made his starting five, you were going to play defense for three hours at practice," Cunningham says, "and never get to touch the ball."
Yet, Kloppenburg swears his teams never neglect offense. And he's right, if you look at things his way. If your pressure defense so scrambles a point guard's brains that he'll throw you the ball, you're then starting your offense right there. You're only taking the ball halfway up the court, instead of all the way. And you're doing so with the defense chasing you.
Now, contrast that with conventional offenses. All those Xs and Os to decipher. All those patterns to memorize. All the self-control and harmony required. Kloppenburg's defense is just going to mess it up, anyway.
Play any of the amazing Payton/Kemp mixtapes, and chances are the most thunderous dunks come off live-ball turnovers initiated by the S-O-S scheme.
But the Sonics also created easy scoring opportunities in less obvious ways. The constant switching, double-teaming, and help-and-recover tactics created matchup confusion the Sonics used to their advantage when going from defense to offense. Unlike most teams that wasted precious seconds looking for an outlet pass to their point guard, the Sonics encouraged any of their players to snatch rebounds out of mid-air and dribble straight up the court. It didn’t matter if the rebounder was Payton, Kemp, Schrempf (and McKey before him), Kendall Gill (and Ricky Pierce before him), Nate McMillan, or even Perkins. All could push the ball right back at a retreating defense scrambling to find their men.
That made a difference even when the fast break was initially cut off. Asking giant center Mark Eaton to guard Kemp in space is, um, not ideal, but the Jazz were forced to cede the matchup because Seattle changed ends too quickly for them to match up properly. The result: an easy drive and score.
Grab-and-go playmakers at every position. Early offense that capitalizes on matchup confusion and easily flows out of stunted fast breaks. Pushing the ball not just after turnovers, but also off defensive rebounds. Those sound like qualities the best defensive teams possess today.
But there’s an Achilles heel the Sonics and present-day Raptors share
Both teams use their pressure defense to give their offenses a head start. That’s brilliant! Except … what happens when their opponent gets used to the pressure and doesn’t get rattled? Suddenly, five men feels like two, not five hundred. As the old cliche goes, the ball moves faster than the man.
That screws up both ends of the floor for the old Sonics and the present-day Raptors. Failed to get a steal or throw off the offense’s timing, and both risked surrendering easy shots. Even when those shots missed, grabbing the rebound became a challenge with players scrambling all over the place. The Sonics were constantly victimized by second-chance points, while the Raptors currently rank 25th in defensive rebounding percentage. You can’t push the pace if you don’t have the ball.
Those easy shots and offensive boards tend to lead to easy buckets, which in turn mitigates the transition sequences they both use to score in bunches. Remove that head start, and both teams struggle to score. The Sonics didn’t have a great shot-creating wing or post scorer to build their sets around until Payton’s offensive game improved later in the decade. Kawhi Leonard was that guy for the Raptors last year, but he’s gone now. While Siakam’s shot creation skills have improved, they’re nowhere near Leonard’s.
Tally those factors up, and the Sonics’ reputation as playoff chokers makes more sense. From 1992-1995, their playoff defensive efficiency was an average of three-and-a-half points higher than their regular-season mark. Teams shot about the same percentage, but turned the ball over much less often, which in turn hurt Seattle’s scoring numbers. You might argue those figures are skewed because the Sonics played better offensive teams in the postseason, but that’s also kinda the point. Playoff teams may experience a shock to the Seattle system at first, but they get used to it with the repeated exposure a playoff series offers.
That’s exactly what happened in the Sonics’ first-round flameouts to the eighth-seeded Nuggets and the upstart Lakers. In 1994, the Nuggets coughed it up on 18.8 percent of their possessions while scoring just 82 points in a 24-point Sonics Game 1 victory. In 1995’s Game 1, the Lakers scored just 71 points and handed Seattle the ball on 18.7 percent of their offensive plays. But the Sonics went just 1-6 in the other seven games of those series while only forcing turnovers on 13 percent of their defensive possessions. The sticker shock of those Game 1 blowouts faded quickly.
Don’t be surprised if the same thing happens to the Raptors in a hypothetical 2020 postseason. It’s a lot easier to make 10 men feel like a hundred when the opponent has no idea you’re coming and no reason to expect you.